This invention is directed to a versatile system of devices for isometric or isotonic exercise and physical therapy. The invention has many of the operational attributes of the exercise and physical therapy apparatus described and claimed in the applicant's co-pending United States applications entitled "Exercise and Therapy Apparatus", and "Isotonic/Isometric Device for Exercise and Physical Therapy", Ser. Nos. 08/364,280 and 08/364,281, both filed Dec. 27, 1994, though the earlier inventions are rather different in structure. This invention usually uses a solid or tubular urethane rod of circular cross section as the principal exercise element, but can utilize a flat plate, a rectangular rod, or the adjustable elastomer torsion device described and claimed in the applicant's co-pending U.S. patent application for "Adjustable Elastomer Torsion Device", Ser. No. 08/262,511, filed Jun. 20, 1994, now U.S. Pat. No. 5,417,407.
A wide variety of different mechanisms have been devised for use in physical therapy for various parts of the human anatomy. Typically, an injured or otherwise impaired arm or wrist requires exercise (physical therapy) to enable the impaired person to recover from the impairment. The same situation may apply to a leg, an ankle, a foot, a back, or some other part of the human anatomy. For some impairments, particularly those involving broken bones, isometric exercises affording substantial resistance are preferred. In trainer's jargon, "no pain, no gain". For other impairments, such as those entailing muscular inflammation, zero or near-zero progressive resistance (isotonic) exercise is often deemed preferable. Many mechanisms can be used for both exercise and therapy purposes. It is difficult, if not impossible, to distinguish between their exercise and therapy attributes.
A principal problem with many exercise and physical therapy devices and systems has been that they usually are not sufficiently versatile to meet the numerous different physical problems to which human beings are prone and to provide either isotonic or isometric exercise, at a desired level, for a given part of the human anatomy. Sometimes this problem is overcome, at least in part, by appropriate provision for changing the component parts of a device to suit the needs of the person requiring exercise or physical therapy. Changeover of this kind may be difficult and time consuming, particularly in a complex exercise device. Furthermore, due to the wide disparity of individual humans as regards their physical attributes such as strength, weight, size, degree of impairment, etc., an apparatus that is quite appropriate and suitable for use by one individual may be totally unacceptable to another person having the same basic impairment, regardless of modification of the device. That is, a therapeutic exercise device may be lacking in the versatility necessary for conversion to use by different individuals even though those individuals have the same basic impairment.